JPH06333220A - Rotary head device - Google Patents

Abstract

PURPOSE:To restrain the deviation quantity in the shaft direction of a locus by providing an elastic supporting section for setting the eccentric direction of a magnetic head on a side opposed to the range of winding a magnetic tape. CONSTITUTION:Rotary bearings 5 and 6 are provided on a fixed shaft 4 projecting from a fixed lower drum 3, by way of these bearings 5 and 6 an upper drum 7 is supported freely rotatably and a magnetic head 8 to be rotated integrally with the drum 7 is provided on the upper drum 7. Two rigid supporting parts T2 and T3 in contact with a peripheral surface corresponding to the bearings 5 and 6 on the fixed shaft 4 is provided together with an elastic supporting section 21 provided on a position 180 deg. from the position 1/2 of an angle formed with these supporting parts T2 and T3 in such a manner that the inner peripheral surfaces of the bearing 5 and 6 are pressed toward the outside of a diameter direction and the section 21 is faced to the side opposite the range of winding a magnetic tape on the drum 7. Then, the eccentric direction of the magnetic head 8 with respect to a lead groove L for guiding the magnetic tape is set on a side opposed to the range of winding the magnetic tape by the working of the elastic supporting section 21 and thus, the deviation quantity of the shaft direction of the magnetic head 8 is restrained to a minimum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head device used in a tape player such as a VTR, and more particularly to a rotary head device which supports an upper drum via a rolling bearing with respect to a fixed shaft fixed to the lower drum. Regarding

[0002]

2. Description of the Related Art A rotary head device used in a conventional tape player is shown in FIG. The rotary head device 1 includes a chassis 2 attached to a tape player main body (not shown), and a lower drum 3 is fixedly connected to the chassis 2 by screw connection or the like.
A fixed shaft 4 is fixed to the central portion of the lower drum 3 in a protruding state. A pair of rolling bearings 5 and 6 are mounted on the fixed shaft 4 so as to be separated from each other in the axial direction.

An upper drum 7 is provided via these rolling bearings 5 and 6. A rotary magnetic head 8 is provided on the lower surface of the peripheral portion of the upper drum 7. The stator 10 of the drive motor 9 is attached to the upper end of the fixed shaft 4.
Are connected by screws or the like.

A rotor 11 of a drive motor 9 is connected to the upper end of the upper drum 7 corresponding to the stator 10. In the rotary head device 1 thus configured, the upper drum 7 is rotationally driven by the rotational driving of the driving motor 9.

Further, as shown in FIG. 16, a pulley 12 is provided on the upper drum 7, and a belt 13 wound around the pulley 12 is attached to the chassis 2 of the motor 1.
There is one that is driven by 4 to rotate the upper drum 7. In the rotary head device 1 as described above, as shown in FIG. 19, the lead groove L for guiding the magnetic tape M is formed on the outer peripheral surface of the lower drum 3. Then, the magnetic head 8 reproduces the locus 8a of the circular motion with high accuracy in the lead groove L, whereby good recording and reproduction can be performed.

However, it is impossible to completely prevent the track 8a of the magnetic head 8 from being eccentric with respect to the lead groove L. One cause of such eccentricity is
A gap B is generated between the fixed shaft 4 and the rolling bearings 5 and 6 as shown in FIG. Due to the generation of the gap B, the rolling bearings 5 and 6 are inclined with respect to the fixed shaft 4 by A degree (actually, it is an extremely small angle but is emphasized in the figure).

The occurrence of such shake has the following effects on magnetic recording and reproduction. For example, when the magnetic head 8 is eccentric in the X direction shown in FIG. 23, the magnetic tape M
22 is wound in the state shown by D1, the locus drawn by the magnetic head 8 draws the locus 8a shown by the range of D1 in FIG. The amount of displacement in the Z direction at this time is d1, and a curve as shown by a locus 8a is drawn with respect to the tracking area TA in FIG.

When the magnetic head M is wound in the state indicated by D3 when the magnetic head 8 is eccentric in the X direction shown in FIG. 23, the locus drawn by the magnetic head 8 is shown in FIG.
Draw a locus 8a indicated by the range D3. The displacement amount at this time is d3, and a curve as shown by a locus 8a is drawn with respect to the tracking area TA in FIG. in this way,
The deviation width d of the locus 8a of the magnetic head 8 depends on the direction of deflection of the magnetic head 8 with respect to the magnetic tape M (lead groove L).
There was a difference between 1 and d3.

For this reason, the reproducibility of the track 8a of the magnetic head 8 is not reliable, and variations easily occur depending on the product, and the track 8a deviates from the tracking area TA as shown in FIG. There was a possibility that the performance would be significantly reduced.

Further, at present, there is a strong demand for lowering the price of the tape player, and it is necessary to increase the grades of the rolling bearings 5 and 6 and use the rolling bearings 5 and 6 with low accuracy. With the conventional composition, it was impossible to achieve high performance under such conditions. Further, as shown in FIG. 17, the pressing force P to the magnetic head 8 generated on the magnetic tape M wound around the drum D becomes the minimum at the winding start point S of the magnetic tape M, and the accuracy of recording and reproducing the magnetic signal is improved. The lowest. That is, the conventional rotary head device 1 uses the magnetic tape M
The recording start point S had the drawback that the recording and reproducing performance was the worst.

[0011]

The eccentricity of the magnetic head with respect to the lead groove formed on the lower drum cannot be completely eliminated even by highly accurate processing. However, by selecting the winding range of the magnetic tape, the deviation of the locus drawn by the magnetic head can be minimized. However, heretofore, there has been no rotary head device having such a technical idea and a configuration for realizing the same.

Further, the pressing force of the magnetic head contacting the magnetic tape wound around the drum is minimized at the winding start point of the magnetic tape, and the recording and reproducing accuracy of the magnetic signal is most lowered. That is, the conventional rotary head device has a drawback that the recording and reproducing performance is the lowest at the winding start point of the magnetic tape.

Therefore, the present invention provides a rotary head device which can minimize the deviation of the trajectory drawn by the magnetic head by selectively arranging the eccentric direction of the magnetic head with respect to the magnetic tape (lead groove). It is also an object of the present invention to provide a rotary head device capable of providing high performance even when the precision of parts is low, by improving the pressing force on the magnetic head at the winding start point of the magnetic tape.

[0014]

According to a first aspect of the present invention, a fixed shaft is provided so as to project from a fixed lower drum, and a rolling bearing is annularly mounted on the fixed shaft, and the upper drum is provided through the rolling bearing. Is rotatably supported, and two rigid support portions abutting on the inner peripheral surface of the rolling bearing are provided on the peripheral surface of the fixed shaft at a predetermined angle, and the elastic support portion has an angle formed by the two rigid support portions of the fixed shaft. It is arranged at a position of approximately 180 degrees from the position of 1/2 and is provided on the side opposite to the winding range of the magnetic tape around the drum, and is configured so as to urge the inner peripheral surface of the rolling bearing outward in the radial direction. The rotary head device.

According to a second aspect of the present invention, a fixed shaft is provided so as to project from the fixed lower drum, and a pair of rolling bearings are annularly mounted at a predetermined distance from the fixed shaft. The upper drum is rotatably supported, and two rigid support portions, which are in contact with the inner peripheral surface of the rolling bearing, are provided on the peripheral surface of the fixed shaft.
Provided at an angle of 120 degrees, the elastic support member is provided at an angle of approximately 120 degrees from the rigid support portion, and is approximately 1 from a position of 1/2 of the winding angle of the magnetic tape around the drum.
The rotary head device is provided at a position of 80 degrees and configured so as to bias the inner peripheral surface of the rolling bearing in the same radial outer direction.

According to a third aspect of the present invention, the elastic supporting member includes a guide member that abuts against the inner ring of the rolling bearing, and a press-fitting member that is interposed between the fixed shaft and the guide member. The rotary head device.

According to a fourth aspect of the present invention, the elastic supporting member includes a guide member that abuts against the inner ring of the rolling bearing, and a press-fitting member that is interposed between the fixed shaft and the guide member. The rotary head device.

According to a fifth aspect of the present invention, a fixed shaft is projectingly provided on the fixed lower drum, and a rolling bearing is mounted on the fixed shaft.
An upper drum rotatably supported via a rolling bearing is provided, a rotary magnetic head is provided on the upper drum, and the inner surface of the rolling bearing is separated by a predetermined angle from the circumferential surface corresponding to the rolling bearing of the fixed shaft. Two rigid support portions that come into contact with each other are provided, and the inner peripheral surface of the rolling bearing is attached at a position approximately 180 degrees from the position of 1/2 of the angle formed by the two rigid support portions of the fixed shaft, with the inner peripheral surface facing outward in the radial direction. An elastic supporting portion for urging is provided, and the elastic supporting portion is arranged at a position approximately 180 degrees from the position of 1/2 of the winding angle of the magnetic tape around the drum, and further, the winding start point of the magnetic tape around the drum and the elasticity. In the rotary head device, a drive motor that rotationally drives the upper drum via a belt is arranged within an angle range between the position where the support portion is arranged.

According to a sixth aspect of the present invention, a fixed shaft is projectingly provided on a fixed lower drum, and the upper drum is rotatably supported on the fixed shaft via a rolling bearing, and the upper drum is provided with a rotary magnet. In the rotary head device, a head is provided, and the maximum eccentric portion in a state where the center of the locus of the magnetic head and the axis of the fixed shaft are parallel to each other substantially coincides with the winding start point of the magnetic tape.

[0020]

According to the first aspect of the present invention, the rolling bearing of the rolling bearing is composed of the two rigid support portions provided on the peripheral surface of the fixed shaft at a predetermined angle and the elastic support portion. The inner ring can be held. Further, the midpoint of the two rigid supports is configured to correspond to the midpoint of the winding angle of the magnetic tape. The elastic supporting portion is located at the position opposite to the winding range of the magnetic tape and urges the inner ring of the rolling bearing outward in the radial direction. Reproducibility can be improved.

According to the configuration of claim 2 of the present invention,
The position of 1/2 (approximately 60 degrees) of the two rigid support portions provided on the peripheral surface of the fixed shaft at an angle of approximately 120 degrees is approximately 1/2 of the winding angle of the magnetic tape wound around the drum. In addition, the elastic support portion is provided between the fixed shaft and the rolling bearing at a position approximately 180 degrees from the position of 1/2 of the winding angle of the magnetic tape, so that the inner ring of the rolling bearing is arranged in the radial direction. Since it is biased to the outside, it is possible to enhance the reproducibility of the magnetic head locus while ensuring sufficient support rigidity for the upper drum.

According to the structure of claim 3 of the present invention,
When the elastic support portion is configured to include a guide member that abuts on the inner ring of the rolling bearing and a press-fitting member that is interposed between the fixed shaft and the guide member, when the rolling bearing is annularly mounted on the fixed shaft. First, without using the guide member and the press-fitting member, the rolling bearing can be mounted on the fixed shaft, and the press-fitting member can be inserted later by using the guide member as a guide, so that it is possible to apply the axial force to the rolling bearing. The elastic support portion can be formed.

According to the configuration of claim 4 of the present invention,
When the elastic support portion is configured to include a guide member that abuts on the inner ring of the rolling bearing and a press-fitting member that is interposed between the fixed shaft and the guide member, when the rolling bearing is annularly mounted on the fixed shaft. Since the guide member and the press-fitting member are annularly mounted without being inserted, and the press-fitting member can be inserted later by using the guide member as a guide, the elastic support portion can be formed without applying the axial force input to the rolling bearing.

According to the structure of claim 5 of the present invention,
On the peripheral surface of the fixed shaft corresponding to the rolling bearing, two rigid support portions are formed which are in contact with the peripheral surface of the rolling bearing at a predetermined angle, and the position of about 1/2 of the angle formed by these rigid support portions is formed. The elastic support portion is provided at a position of 180 degrees from 180 degrees, and the position of approximately 1/2 of the angle formed by the two rigid support portions corresponds to the position of approximately 1/2 of the winding angle of the magnetic tape wound around the drum, By providing the drive motor for driving the upper drum via the belt within the angular range between the winding start point of the magnetic tape and the arrangement position of the elastic support portion,
It is possible to prevent the stress applied to the fixed shaft from being applied to the elastic support portion due to the winding of the belt.

According to the structure of claim 6 of the present invention,
The pressing force of the magnetic tape on the magnetic head at the winding start point is adjusted by making the maximum eccentric part in a state where the center of the trajectory of the magnetic head and the axis of the fixed axis are parallel to the winding start point of the magnetic tape. Can be improved. The deviation of the magnetic head due to the deviation of the parallel axes does not affect the recording and reproducing performance.

[0026]

EXAMPLE A first example of the present invention will be described. First, a schematic configuration of the rotary head device 1 is shown in FIG.
This will be described with reference to FIG. The rotary head device 1 includes a chassis 2 attached to a tape player main body (not shown), and a lower drum 3 is screwed to the chassis 2 by a screw connection or the like.
It is firmly bonded. A lead groove L for guiding the magnetic tape M is formed on the outer peripheral surface of the lower drum 3. Further, a fixed shaft 4 whose positional relationship with the lead groove L is precisely set is fixed to the central portion of the lower drum 3 in a protruding state, and is fixed to the fixed shaft 4 in the axial direction. A pair of rolling bearings 5 and 6 are annularly mounted.

An upper drum 7 is provided via the rolling bearings 5 and 6. A rotary magnetic head 8 is provided on the lower surface of the peripheral portion of the upper drum 7. The stator 10 of the drive motor 9 is attached to the upper end of the fixed shaft 4.
Are connected by screws or the like.

A rotor 11 of a drive motor 9 is connected to the upper end of the upper drum 7 corresponding to the stator 10. In the rotary head device 1 thus configured, the upper drum 7 is rotationally driven by the rotation of the drive motor. The fixed shaft structure of the rotary head device 1 configured as described above will be described in detail.

The fixed shaft 4 shown in FIG. 1 is constructed as shown in FIGS. 4, 7 and 8, for example.
The fixed shaft 4 is formed in a shape in which other peripheral surface portions are cut off, leaving four peripheral surface portions T1, T2, T3, T4 out of the peripheral surfaces facing the inner rings 5a, 6a of the rolling bearings 5, 6. Has been done. That is, the four peripheral surface portions T1 to T4 are formed in a peripheral surface shape having the same center and the same radius, and the four inner peripheral surfaces of the inner rings 5a and 6a of the rolling bearings 5 and 6 have the same inner diameter. All of the peripheral surface portions T1 to T4 are the inner ring 5a,
It comes into contact with 6a.

Then, two of the peripheral surface portions T2, T
3 is used as a rigid support part, and other peripheral surface parts T1, T4
Is the outer diameter of the fixed shaft 4 and the inner rings 5a, 6a of the rolling bearings 5, 6.
It is prepared as a supplement for the case of matching. The other peripheral surface portions 4a, 4b, 4c, 4d that have been cut off, leaving the two rigid support portions T2, T3 and the other peripheral surface portions T1, T4.
For example, the surfaces adjacent to each other are formed in a plane shape at an angle of approximately 90 degrees, and the surfaces facing each other are arranged substantially parallel to each other.

Further, the two rigid support portions T2, T3
As shown in FIG. 1, approximately midpoints Tc2 and Tc3 of the circumferential dimension of each circumferential surface are formed at an angle of approximately 120 degrees.

Further, the two rigid supporting portions T2, T3
An elastic support portion 21 is provided at a position 4a that is approximately 120 degrees away from the intermediate points TC2 and TC3. The elastic support portion 21 is, for example, a press-fitting member 23 that is inserted into a concave groove portion 22 that is formed along the axial direction with respect to the peripheral surface portion 4 a that is cut in a planar shape of the fixed shaft 4, and the press-fitting member 23. And a guide member 24 that comes into contact with the inner rings 5a and 6a of the rolling bearings 5 and 6. The press-fitting member 23 is, for example, a spring member having a C-shaped cross section in the major axis direction and having elasticity, and the guide member 24 is, for example, a rectangular metal plate whose central portion is formed in a convex shape.

Here, the elastic support portion 21 for the fixed shaft 4 is provided.
The assembling step will be described with reference to FIGS. 9 and 10. First, the rolling bearings 5 and 6 are attached to the fixed shaft 4. After that, the guide member 24 is inserted between the peripheral surface portion 4a of the fixed shaft 4 and the inner rings 5a and 6a. Then, the press-fitting member 23 is press-fitted between the guide member 24 and the fixed shaft 4 along the concave groove portion 22 of the peripheral surface portion 4 a. Thus, by inserting the press-fitting member 23 using the guide member 24 as a guide, it is possible to prevent the axial force from acting on the rolling bearings 5 and 6, so that the rolling bearings are smooth and do not impair the accuracy of the bearing. Assembly can be done.

The fixed shaft 4 provided with the elastic supporting portion 21 having the above-described structure has the inner rings 5a, 6a of the rolling bearings 5, 6.
When the inner diameter and the outer diameter of the inner ring 5a are the same as those of the inner ring 5a, as shown in FIG.
6a is supported. At this time, the elastic support portion 21 also elastically abuts on the inner rings 5a and 6a separately from the peripheral surfaces T1 to T4.

When the inner diameters of the inner races 5a and 6a are larger than the outer diameter of the fixed shaft 4, the press-fitting member 23 of the elastic supporting portion 21 elastically expands to guide the guide member, as shown in FIG. 24 is adapted to contact the inner rings 5a, 6a. The inner peripheral surfaces of the inner rings 5a and 6a are supported by the rigid support portions T2 and T3 and the guide member 24 of the elastic support portion 21 at three points.

That is, even if there is a gap between the fixed shaft 4 and the inner rings 5a and 6a of the rolling bearings 5 and 6, the gap is set in the predetermined direction (on the side where the elastic support portion 21 is provided). Moreover, by supporting at three points, this state can be maintained fixed and the eccentric direction of the trajectory 8a of the magnetic head 8 can be determined. In the conventional structure, if a gap is generated, only one point or two points can be supported, and the eccentric direction cannot be fixed. However, according to the above-described structure, three points can be supported. The eccentric direction of the locus 8a of the head 8 can be set, and the rotation of the upper drum 7 can be stabilized.

When the fixed shaft 4 constructed as described above is incorporated into the rotary head device 1, when the wrap angle of the magnetic tape M moving in the direction of arrow R is 180 degrees, the arrangement as shown in FIG. The highest precision can be obtained by establishing a relationship. That is, the intermediate point G between the rigid support portions T2 and T3 is arranged at a position ½ of the winding angle 180 degrees of the magnetic tape M, and the elastic support portion is provided at a position (180 degrees) opposite to the intermediate point G. 21 is arranged. Here, the inner rings 5a, 6a of the rolling bearings 5, 6 are supported at three points indicated by arrows F1 to F3 shown in the figure.

With respect to the effect of improving the recording and reproducing accuracy of the magnetic tape M by such a configuration, FIG. 11 and FIG.
Will be described with reference to. At the wrap angle D1 of 180 degrees shown in the figure, the magnetic head 8 for the magnetic tape M
It is the movement of the magnetic head 8 in the direction indicated by Y in the figure that has the greatest effect on the displacement amount d1 (Z direction) of the locus 8a. For this reason, it is necessary to minimize the movement of the magnetic head 8 in the Y direction. As described above, the eccentric direction of the magnetic head 8 is set in the X direction by the elastic support portion 21, and the rigid support portion is set. By giving rigidity to the contact side of the magnetic tape M by T2 and T3, the shift amount d1 of the locus 8a can be minimized. As a result, the reproduction accuracy of the track 8a of the magnetic head 8 with respect to the lead groove L can be improved, and the recording and reproducing performance of the magnetic tape M can be improved. That is, the shift amount d1 shown in FIG. 20 can be set, and the trajectory 8a can be easily drawn in the tracking area TA.

From the above, it is possible to provide the rotary head device 1 having high recording and reproducing accuracy even if the parts accuracy is low. In the above-described embodiment, the position of the elastic support portion 21 is on the opposite side of the position G which is 1/2 of the winding angle of 180 degrees of the magnetic tape M. However, the position is not limited to this, and is within the winding range of the magnetic tape M. Similar effects can be obtained if the positions do not face each other. The second embodiment of the present invention will be described below. The rotary head device 1 shown in FIG.
The magnetic tape M has a wrap angle of 90 degrees, and in this case also, as in the first embodiment, the rigid support portions T2, T are provided.
The intermediate position G of 3 is arranged so as to correspond to the position of 1/2 of the winding angle of 90 degrees of the magnetic tape M.

With this structure, the magnetic tape M can be wound in the state indicated by D2 in FIGS. 11 and 12. Thereby, the amount d2 of the trajectory 8a of the magnetic head 8 displaced in the axial direction Z in the range corresponding to the magnetic tape M can be suppressed to the minimum. Below, fixed shaft 4
A modified example of the elastic support portion 21 provided for the above will be described with reference to FIGS. 5 and 6. The elastic supporting portion 21 shown in FIG. 5 is a curved plate in which the guide member 24 is made of an elastic member such as a rigid resin, and the press-fitting member 23 is a rigid member such as a metallic cylindrical rod. Even with such a configuration, when the press-fitting member 23 is press-fitted, the guide member 24 elastically deforms and guides the press-fitting member 23, so that the rolling bearings 5 and 6 can be assembled without applying an axial force.

It is also possible to use an elastic metal plate or the like as shown in FIG. 6 as the elastic support portion 21. Further, the elastic support portion 21 formed of such a one-piece member
The material is not limited to metal, but the same effect can be obtained with resin or the like. A third embodiment of the present invention will be described. The rotary head device 1 shown in FIG. 3 has a magnetic tape M with a wrap angle of, for example, 180 degrees, but is equipped with an external driving motor 14 so that the belt 13 drives the upper drum 7 to rotate. ing.

The motor 14 is arranged so as to be arranged between the position where the elastic support portion 21 is provided and the point S where the magnetic tape M starts to wind. With such a configuration, it is possible to secure a sufficient distance from the audio head AH provided on the winding side of the magnetic tape M to the motor 14, and to prevent generation of magnetic noise. Further, due to the winding of the belt 13, bending stresses F4 and F5 act on the fixed shaft 4. Due to the bending stresses F4 and F5, the upper drum 7 is pressed toward the winding start position S side of the magnetic tape M. This allows
The upper drum 7 is moved to the winding start position S side of the magnetic tape M, the contact pressure of the magnetic head 8 to the magnetic tape M at the winding start position S can be improved, and the recording and reproducing performance can be improved.

In any of the rotary head devices 1 shown in FIGS. 1 to 3, the pressing force of the magnetic head 8 on the magnetic tape M at the winding start position S of the magnetic tape M is at any other position. This is the position where the recording and reproducing performance is the lowest. Therefore, the amount of eccentricity Pd shown in FIG. 13 (the eccentricity Pd in the parallel state between the fixed shaft 4 and the upper drum 7 that occurs even if the structure is manufactured with high precision)
Can be utilized as shown in FIG. Here, the eccentricity Pd in the parallel state is the locus 8 of the magnetic head 8.
It does not adversely affect a and contributes only to the pressing force of the magnetic head 8 against the magnetic tape M.

As shown in the figure, the maximum eccentric side surface LS of the upper drum 7 is made to correspond to the winding start point S of the magnetic tape M, so that the maximum radial projection position of the magnetic head is the winding start point of the magnetic tape M. Can be located at S. As a result, in the conventional structure, the contact pressure of the magnetic head with respect to the magnetic tape M is the lowest at the winding start point S of the magnetic tape M, whereas the arrow F6 in FIGS.
A pressing force F6 can be generated as indicated by. That is, high recording and reproducing performance can be obtained even at the winding start point S of the magnetic tape M.

[0045]

According to the first aspect of the present invention, since the eccentric direction of the magnetic head can be set on the side opposite to the winding range of the magnetic tape, the rotational locus of the magnetic head is higher than the lead groove (magnetic tape). It can be reproduced with accuracy and the amount of axial deviation of the magnetic head can be minimized. Further, by selectively arranging the magnetic head in the eccentric direction, the eccentric direction of the locus of the magnetic head is left to the random arrangement in the conventional structure, and the reproducibility of the locus is low in mass production. Therefore, the reproducibility of the locus in mass production can be made more reliable.

Further, by providing the elastic support portion on the fixed shaft, it is possible to provide a rotary head device having high recording / reproducing performance even if the fitting accuracy between the fixed shaft and the inner ring of the rolling bearing is poor.

According to the invention of claim 2, a fixed shaft having an elastic supporting portion is provided at a position of approximately 180 degrees from a position of 1/2 of the winding angle of the magnetic tape, and corresponds to the range of the winding angle of the magnetic tape. Since the fixed shaft provided with the two rigid support portions at the position can reproduce the trajectory of the magnetic head with respect to the lead groove (magnetic tape) with high accuracy, the fixed shaft and the rolling bearing with the same accuracy were used. It is possible to provide a rotary head device that can obtain extremely high recording and reproducing performance as compared with the conventional structure.

According to the third aspect of the invention, in addition to the effect obtained in the first aspect, the elastic supporting portion is configured by being separated into the guide member and the press-fitting member. Since the guide member abuts the inner ring of the rolling bearing to guide the press-fitting member, it is possible to prevent the axial force from acting on the rolling bearing, so that highly accurate assembly can be facilitated.

According to the invention of claim 4, in addition to the effect obtained in claim 2, since the guide member guides when the press-fitting member is inserted, the elastic support portion is provided between the fixed shaft and the rolling bearing. The work of inserting it into the can becomes easy. Further, it is possible to prevent axial stress from being applied to the rolling bearing when the press-fitting member is press-fitted.

According to the fifth aspect of the invention, the drive motor provided outside is arranged between the winding start point of the magnetic tape and the arrangement position of the elastic support portion, so that the magnetic force applied to the audio head or the like is magnetically increased. It is possible to prevent the influence and reduce the storage space in the VTR main body.

According to the invention of claim 6, by arranging the direction of the deflection of the locus of the magnetic head in the parallel state with respect to the fixed axis 4 at the winding start point of the magnetic tape, the winding time of the magnetic tape is started. The contact pressure of the magnetic head can be increased, and reliable magnetic recording and reproduction can be performed from the contact start point between the magnetic tape and the magnetic head.

[Brief description of drawings]

FIG. 1 is a plan view of a rotary head device according to an embodiment of the present invention, in which a magnetic tape has a wrap angle of 180 degrees.

FIG. 2 is a plan view of a rotary head device in which another embodiment of the present invention has a magnetic tape wrap angle of 90 degrees.

FIG. 3 is a plan view of a rotary head device according to another embodiment of the present invention, in which a drive motor is provided outside a cylinder.

FIG. 4 is a perspective view showing a fixed shaft and an elastic support portion according to an embodiment of the present invention.

FIG. 5 is a perspective view showing a fixed shaft and an elastic support portion, which is another embodiment of the present invention.

FIG. 6 is a perspective view showing a fixed shaft and an elastic support portion according to another embodiment of the present invention.

FIG. 7 is a plan view showing a state where the diameter of the fixed shaft matches the inner diameter of the inner ring of the rolling bearing, which is an embodiment of the present invention.

FIG. 8 is a plan view showing a case where the diameter of the fixed shaft is smaller than the inner diameter of the inner ring of the rolling bearing, which is an embodiment of the present invention.

FIG. 9 is a front sectional view showing a step of mounting an elastic support portion between a fixed shaft and a rolling bearing.

FIG. 10 is a front sectional view showing a state in which an elastic support portion is mounted between a fixed shaft and a rolling bearing.

FIG. 11 is an explanatory diagram illustrating the relationship between the amount of shake of the magnetic head in the Z direction and the winding range of the magnetic tape.

FIG. 12 is a plan view showing a winding angle of a magnetic tape around a rotary head device.

FIG. 13 is a half cross-sectional view of the rotary head device showing a state where the axis of the fixed shaft and the center of the locus of the magnetic head are parallel and eccentric.

FIG. 14 is a plan view of a rotary head device showing a state where a fixed shaft and an upper drum (magnetic head) are eccentric in a parallel state.

FIG. 15 is a front cross-sectional view showing the basic configuration of a general rotary head device.

FIG. 16 is a front sectional view showing the basic structure of a general rotary head device.

FIG. 17 is a contact pressure diagram of the magnetic head showing the winding pressure of the magnetic tape around the magnetic head in the conventional rotary head device.

FIG. 18 is a front cross-sectional view showing a state of a fixed shaft of a conventional rotary head device and a rolling bearing mounted with a gap therebetween.

FIG. 19 shows a state in which a magnetic tape is wound around a conventional rotary head device, and X, Y, Z for explaining the eccentric direction and the like.
The perspective view which shows a direction.

FIG. 20 is an explanatory diagram showing a conventional example, in which the deviation of the trajectory of the magnetic head in the Z direction is associated with the tracking area when the trajectory of the magnetic head is eccentric.

FIG. 21 is an explanatory diagram showing another example of a conventional example in which the deviation of the trajectory of the magnetic head in the Z direction is associated with the tracking area when the trajectory of the magnetic head is eccentric.

FIG. 22 is an explanatory diagram showing a relationship between the deviation amounts d1 and d3 of the magnetic head in the Z direction and the winding positions D1 and D3 of the magnetic tape when the locus of the magnetic head is eccentric, which is a conventional example.

FIG. 23 is a conventional example, where the winding state of the magnetic tape is D1, D when the locus of the magnetic head is eccentric in the X direction.
The top view shown by 3.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotary head device 3 lower drum 4 fixed shaft 5,6 rolling bearing 7 upper drum 8 magnetic head 14 drive motor 21 elastic support portion 23 press fit member 24 guide member T2, T3 rigid support portion L lead groove

Claims (6)

[Claims] 1. A fixed shaft projecting from a fixed lower drum, a rolling bearing mounted around the fixed shaft, an upper drum rotatably supported via the rolling bearing, and an upper drum. A magnetic head that is provided and rotates together with the upper drum, two rigid support portions that are provided at a predetermined angle on the peripheral surface of the fixed shaft corresponding to the rolling bearing, and contact the inner peripheral surface of the rolling bearing, and the fixed shaft. Is arranged at a position of approximately 180 degrees from the position of 1/2 of the angle formed by the two rigid supporting portions of the rolling bearing, urges the inner peripheral surface of the rolling bearing outward in the radial direction, and attaches the magnetic tape to the drum. A rotary head device, comprising: an elastic supporting portion provided on the side opposite to the winding range. 2. A fixed shaft projectingly provided on a fixed lower drum, a pair of rolling bearings annularly mounted at a predetermined distance from the fixed shaft, and the fixed shaft via a pair of rolling bearings. The upper drum rotatably supported with respect to the rotary drum, the rotary magnetic head provided on the upper drum, and the peripheral surface of the fixed shaft corresponding to the respective rolling bearings are provided at an angle of approximately 120 degrees to allow rolling. From the two rigid support portions that come into contact with the inner peripheral surface of the bearing and the two rigid support portions of the fixed shaft, approximately 12
The rolling bearings are arranged at an angle of 0 degree, and are provided so as to urge the inner peripheral surfaces of the respective rolling bearings in the same radial outer direction, and 1 / of the winding angle of the magnetic tape around the drum.
2. A rotary head device comprising: an elastic support portion provided at a position approximately 180 degrees from the position 2. 3. The rotary head according to claim 1, wherein the elastic support portion includes a guide member that comes into contact with the inner ring of the rolling bearing, and a press-fitting member that is interposed between the fixed shaft and the guide member. apparatus. 4. The rotary head according to claim 2, wherein the elastic support portion includes a guide member that abuts the inner ring of the rolling bearing, and a press-fitting member that is interposed between the fixed shaft and the guide member. apparatus. 5. A fixed shaft projecting from a fixed lower drum, a rolling bearing mounted around the fixed shaft, an upper drum rotatably supported via the rolling bearing, and an upper drum. Two rigid support portions, which are provided at a predetermined angle on the circumferential surface of the fixed shaft and corresponding to the rolling bearing of the fixed shaft and are in contact with the inner circumferential surface of the rolling bearing, and the fixed shaft It is arranged at a position of approximately 180 degrees from the position of 1/2 of the angle formed by the two rigid support parts, urges the inner peripheral surface of the rolling bearing outward in the radial direction, and the winding range of the magnetic tape around the drum. Is placed within an angular range between the elastic support provided at a position substantially opposite to the position where the magnetic tape is wound around the drum and the position where the elastic support is arranged, and the upper drum is driven to rotate via the belt. And a drive motor for Turning head device. 6. A fixed shaft protruding from a fixed lower drum, an upper drum rotatably supported on the fixed shaft via a rolling bearing, and a rotary magnetic head provided on the upper drum. In the rotary head device, the rotary head device is characterized in that the maximum eccentric portion in a state where the center of the locus of the magnetic head and the axis of the fixed shaft are parallel to each other substantially coincides with the winding start point of the magnetic tape.